U.S. patent number 8,620,341 [Application Number 13/149,400] was granted by the patent office on 2013-12-31 for method and apparatus for adjusting bandwidth allocations in a wireless network.
This patent grant is currently assigned to Fujitsu Limited. The grantee listed for this patent is Wei-Peng Chen, Chenxi Zhu. Invention is credited to Wei-Peng Chen, Chenxi Zhu.
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United States Patent |
8,620,341 |
Zhu , et al. |
December 31, 2013 |
Method and apparatus for adjusting bandwidth allocations in a
wireless network
Abstract
In accordance with particular embodiments, a method includes
providing one or more network tuning constants associated with one
or more base stations of a wireless network. The network tuning
constants are configured to adjust an equilibrium point of a first
bandwidth allocation among the one or more base stations. The
method also includes receiving one or more signal performance
values from each of the one or more base stations in the wireless
network. The method further includes determining whether at least
one of the one or more network tuning constants needs to be
adjusted. The method additionally includes, upon determining that
at least one of the one or more network tuning constants needs to
be adjusted, adjusting the one or more network tuning constants
based at least in part on the one or more signal performance
values.
Inventors: |
Zhu; Chenxi (Palo Alto, CA),
Chen; Wei-Peng (Fremont, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Zhu; Chenxi
Chen; Wei-Peng |
Palo Alto
Fremont |
CA
CA |
US
US |
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|
Assignee: |
Fujitsu Limited (Kawasaki-shi,
JP)
|
Family
ID: |
44788564 |
Appl.
No.: |
13/149,400 |
Filed: |
May 31, 2011 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20110256878 A1 |
Oct 20, 2011 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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PCT/US2011/020911 |
Jan 12, 2011 |
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PCT/US2011/020912 |
Jan 12, 2011 |
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61323209 |
Apr 12, 2010 |
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Current U.S.
Class: |
455/453;
455/452.2; 370/236.1; 455/452.1; 455/450; 370/329 |
Current CPC
Class: |
H04W
24/02 (20130101); H04W 84/045 (20130101); H04W
92/20 (20130101); H04W 28/18 (20130101); H04W
28/16 (20130101) |
Current International
Class: |
H04W
72/00 (20090101); H04W 4/00 (20090101); H04L
1/00 (20060101) |
Field of
Search: |
;455/450 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1 098 546 |
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May 2001 |
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EP |
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2 106 171 |
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Sep 2009 |
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EP |
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WO 2011/060310 |
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May 2011 |
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WO |
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Other References
Extended European search report issued by the EPO; Application No.
12150811.3-2412, Mar. 26, 2012. cited by applicant.
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Primary Examiner: Ho; Huy C
Attorney, Agent or Firm: Baker Botts L.L.P.
Parent Case Text
RELATED APPLICATION
The present application is a Continuation-in-Part of International
Application No. PCT/US2011/020911, filed Jan. 12, 2011 entitled
"Method and Apparatus for Centralized Allocation of Bandwidth in a
Wireless Network" and International Application No.
PCT/US2011/020912, filed Jan. 12, 2011 entitled "Method and
Apparatus for Locally Managed Allocation of Bandwidth in a Wireless
Network," which both International Applications claim the benefit
of U.S. Provisional Application Ser. No. 61/323,209, entitled
"Distributed and Hybrid Control for Wireless Networks," filed Apr.
12, 2010.
Claims
What is claimed is:
1. A method, comprising: providing one or more network tuning
constants associated with one or more base stations of a wireless
network, the network tuning constants configured to adjust an
equilibrium point of a first bandwidth allocation among the one or
more base stations; receiving one or more signal performance values
from each of the one or more base stations in the wireless network;
determining whether at least one of the one or more network tuning
constants needs to be adjusted; and upon determining that at least
one of the one or more network tuning constants needs to be
adjusted, adjusting the one or more network tuning constants based
at least in part on the one or more signal performance values.
2. The method of claim 1, wherein the one or more network tuning
constants comprises at least a first network tuning constant and at
least a second network tuning constant, the first network tuning
constant a global network tuning constant comprising a common value
for each of the one or more base stations and the second network
tuning constant a local network tuning constant that differs
between at least two of the one or more base stations.
3. The method of claim 1, wherein adjusting the one or more network
tuning constants comprises adjusting the one or more network tuning
constants to move the equilibrium point towards a rate fair
equilibrium point.
4. The method of claim 1, wherein adjusting the one or more network
tuning constants comprises adjusting the one or more network tuning
constants to move the equilibrium point towards a resource fair
equilibrium point.
5. The method of claim 1: further comprising receiving a request to
adjust the one or more network tuning constants of a subset of the
one or more base stations; and wherein adjusting the one or more
network tuning constants is further based on the request to adjust
the one or more network tuning constants of a subset of the one or
more base stations.
6. The method of claim 1, further comprising receiving a request to
adjust the equilibrium point of the first bandwidth allocation
among the one or more base stations.
7. The method of claim 1: further comprising comparing the
equilibrium point of the first bandwidth allocation to a
predetermined equilibrium point, and wherein determining whether at
least one of the one or more network tuning constants needs to be
adjusted is further based on the comparison of the equilibrium
point of the first bandwidth allocation to a predetermined
equilibrium point.
8. A system comprising: an interface configured to: provide one or
more network tuning constants associated with one or more base
stations of a wireless network, the network tuning constants
configured to adjust an equilibrium point of a first bandwidth
allocation among the one or more base stations; and receive one or
more signal performance values from each of the one or more base
stations in the wireless network; and a processor coupled to the
interface and configured to: determine whether at least one of the
one or more network tuning constants needs to be adjusted; and upon
determining that at least one of the one or more network tuning
constants needs to be adjusted, adjust the one or more network
tuning constants based at least in part on the one or more signal
performance values.
9. The system of claim 8, wherein the one or more network tuning
constants comprises at least a first network tuning constant and at
least a second network tuning constant, the first network tuning
constant a global network tuning constant comprising a common value
for each of the one or more base stations and the second network
tuning constant a local network tuning constant that differs
between at least two of the one or more base stations.
10. The system of claim 8, wherein the processor configured to
adjust the one or more network tuning constants is further
configured to adjust the one or more network tuning constants to
move the equilibrium point towards a rate fair equilibrium
point.
11. The system of claim 8, wherein the processor configured to
adjust the one or more network tuning constants is further
configured to adjust the one or more network tuning constants to
move the equilibrium point towards a resource fair equilibrium
point.
12. The system of claim 8, wherein: the interface is further
configured to receive a request to adjust the one or more network
tuning constants of a subset of the one or more base stations; and
the processor is further configured to adjust the one or more
network tuning constants based on the request to adjust the one or
more network tuning constants of a subset of the one or more base
stations.
13. The system of claim 8, wherein the interface is further
configured to receive a request to adjust the equilibrium point of
the first bandwidth allocation among the one or more base
stations.
14. The system of claim 8, wherein: the processor is further
configured to compare the equilibrium point of the first bandwidth
allocation to a predetermined equilibrium point, and wherein the
processor configured to determine whether at least one of the one
or more network tuning constants needs to be adjusted based on the
comparison of the equilibrium point of the first bandwidth
allocation to a predetermined equilibrium point.
15. Logic embodied in a tangible and non-transitory computer
readable medium that when executed is configured to: provide one or
more network tuning constants associated with one or more base
stations of a wireless network, the network tuning constants
configured to adjust an equilibrium point of a first bandwidth
allocation among the one or more base stations; receive one or more
signal performance values from each of the one or more base
stations in the wireless network; determine whether at least one of
the one or more network tuning constants needs to be adjusted; and
upon determining that at least one of the one or more network
tuning constants needs to be adjusted, adjust the one or more
network tuning constants based at least in part on the one or more
signal performance values.
16. The logic of claim 15, wherein the one or more network tuning
constants comprises at least a first network tuning constant and at
least a second network tuning constant, the first network tuning
constant a global network tuning constant comprising a common value
for each of the one or more base stations and the second network
tuning constant a local network tuning constant that differs
between at least two of the one or more base stations.
17. The logic of claim 15, configured to adjust the one or more
network tuning constants is further configured to adjust the one or
more network tuning constants to move the equilibrium point towards
a rate fair equilibrium point.
18. The logic of claim 15, configured to adjust the one or more
network tuning constants is further configured adjust the one or
more network tuning constants to move the equilibrium point towards
a resource fair equilibrium point.
19. The logic of claim 15, further configured to: receive a request
to adjust the one or more network tuning constants of a subset of
the one or more base stations; and adjust the one or more network
tuning constants based on the request to adjust the one or more
network tuning constants of a subset of the one or more base
stations.
20. The logic of claim 15, further configured to receive a request
to adjust the equilibrium point of the first bandwidth allocation
among the one or more base stations.
21. The logic of claim 15, further configured to: compare the
equilibrium point of the first bandwidth allocation to a
predetermined equilibrium point, and determine whether at least one
of the one or more network tuning constants needs to be adjusted
based on the comparison of the equilibrium point of the first
bandwidth allocation to a predetermined equilibrium point.
Description
TECHNICAL FIELD
The present disclosure relates generally to methods and apparatuses
for adjusting bandwidth allocations in a wireless network.
BACKGROUND
Various wireless technologies (e.g., 3G, 4G, 3GPP Long Term
Evolution (LTE), LTE-Advanced (LTE-A), WiMAX, etc.) allow for the
use of small, user installed, base stations, generally referred to
as femto base stations (also known as femtocells in WiMAX or Home
node-B in 3GPP). A femto base station may be provided to a user by
a wireless service provider (WSP). A femto base station may be a
miniature base station that a user may install in a home or office
to enhance signal strength and service quality to endpoints such as
wireless phones or netbooks. The user installs the femto base
station in their home or office, generally referred to herein as a
home or home location, to increase the quality and signal strength
of the local wireless coverage. The femto base station's backhaul
connection to the WSP's network (WSPN) is provided via the user's
home network access (e.g., DSL). The femto base station operates in
a similar wireless fashion (e.g., uses the same licensed frequency
band) to the WSP's macro base stations. Because, a femto base
station operates in a similar wireless fashion to a macro base
station, it may be possible for an endpoint to use the same
wireless service to establish a connection through the femto base
station.
SUMMARY OF THE DISCLOSURE
The teachings of the present disclosure relate to methods and
systems in which, in accordance with particular embodiments, a
method includes providing one or more network tuning constants
associated with one or more base stations of a wireless network.
The network tuning constants are configured to adjust an
equilibrium point of a first bandwidth allocation among the one or
more base stations. The method also includes receiving one or more
signal performance values from each of the one or more base
stations in the wireless network. The method further includes
determining whether at least one of the one or more network tuning
constants needs to be adjusted. The method additionally includes,
upon determining that at least one of the one or more network
tuning constants needs to be adjusted, adjusting the one or more
network tuning constants based at least in part on the one or more
signal performance values.
Technical advantages of particular embodiments include providing a
bandwidth updating algorithm that allows a service provider to
adjust the performance of one or more femto base stations.
Accordingly, the service provider may provide varying levels of
service. Other technical advantages will be readily apparent to one
of ordinary skill in the art from the following figures,
descriptions, and claims. Moreover, while specific advantages have
been enumerated above, various embodiments may include all, some,
or none of the enumerated advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of particular embodiments and
their features and advantages, reference is now made to the
following description, taken in conjunction with the accompanying
drawings, in which:
FIG. 1 depicts an example of a system for adjusting bandwidth
allocations in a wireless network in accordance with particular
embodiments;
FIG. 2 depicts examples of network topologies for adjusting
bandwidth allocations in a wireless network in accordance with
particular embodiments; and
FIG. 3 depicts an example of a method for adjusting bandwidth
allocations in a wireless network in accordance with particular
embodiments.
DETAILED DESCRIPTION OF THE DRAWINGS
Embodiments and their advantages are best understood by referring
to FIGS. 1-3 of the drawings, like numerals being used for like and
corresponding parts of the various drawings.
FIG. 1 depicts an example of a system 100 for adjusting bandwidth
allocations in a wireless network. In the embodiment depicted in
FIG. 1, system 100 includes femto base stations 104, 136, and 140,
macro base station (MBS) 144, endpoints 124 and 128, Internet
service provider (ISP) network 132, wireless service provider (WSP)
network 148, and server 152 coupled as shown. Femto base station
(fBS) 104 may be operable to communicate wirelessly with one or
more endpoints 124 and 128 using a first frequency bandwidth. Femto
base station 104 may have determined the first frequency bandwidth
based on one or more network tuning constants received from server
152. The network tuning constants may be supplied by server 152 to
all the femto base stations (e.g., femto base stations 104, 136,
and 140) in system 100. The values of the network tuning constants
may impact the equilibrium point of system 100. The equilibrium
point may reflect the point at which the wireless resource usage
converges for femto base stations 104, 136 and 140. The equilibrium
point may lie somewhere in the range between rate fair (the femto
base stations provide an approximately equal amount of data
throughput) and resource fair (the femto base stations provide an
approximately equal amount of wireless resources). Femto base
station 104 may receive a measurement of a signal performance from
one or more of endpoints 124 and 128. Femto base station 104 may
communicate an indication of the signal performance to server 152.
Server 152 may determine from at least the indication of signal
performance that one or more network tuning constants should be
changed. Server 152 may then determine and transmit updated network
tuning constants to femto base stations 104, 136, and 140. Femto
base station 104 may use updated network tuning constants to
determine, either directly or indirectly, a second frequency
bandwidth to use to communicate wirelessly with one or more
endpoints 124 and 128. Femto base station 104 may then communicate
wirelessly with at least one of endpoints 124 and 128 using the
second frequency bandwidth.
Femto base station 104 may be any suitable device that is operable
to communicate wirelessly with one or more endpoints, such as 124
or 128. Although particular types of base stations are shown, other
embodiments may include any combination of macro, micro, pico,
femto base stations, and/or any other types of base stations and/or
relay stations. In particular embodiments, any of these base
stations and/or relay stations may be operable to perform some or
all of the functions of femto base station 104 and/or server 152,
as described herein.
In some embodiments, femto base station 104 may be connected to WSP
network 148 through a user's ISP connection from his home or office
through ISP network 132. Because femto base station 104 uses the
user's network (at home, in the office, or any other location where
the user can access the Internet or WSP network 148), the WSP may
not need to provide backhaul access from femto base station 104 to
WSP network 148. The WSP and the ISP may be the same or different
entities with or without a special agreement related to femto base
station 104. Depending on the scenario, femto base station 104 may
be configured to serve either a closed subscription group (CSG)
(e.g., the owner of the base station determines who may access the
base station) or an open subscription group (OSG) (e.g., any
endpoint with an active service contract with the WSP may access
the base station).
In some embodiments, a WSP's wireless network may include numerous
femto base stations that are coupled to WSP network 148. Because
the femto base stations are purchased and installed by users, the
WSP may have little control over the exact locations and/or the
densities of these devices. Because each user and/or home location
may have its own respective femto base station (such as femto base
station 104), there may be a relatively high concentration of femto
base stations within a given area (e.g., an apartment complex). In
some embodiments, a femto base station may use the same licensed
spectrum (e.g., the spectrum licensed by the user's WSP) as the
local macro base stations (e.g., macro base station 144) and relay
stations (not depicted) of the WSP. Thus, in some cases, multiple
femto base stations may share a common wireless channel due to the
limited amount of frequency spectrum available for wireless
communication. These factors may increase the chance and/or
severity of wireless interference between nearby femto base
stations and/or other base stations or relay stations, which in
turn may inhibit the performance of a femto base station and/or
other base station or relay station affected by the
interference.
One way to reduce the interference between femto base stations is
to control the frequency bandwidth allocated to each femto base
station. Frequency bandwidth may refer to an amount of a frequency
spectrum that is used for wireless communication. In some
embodiments, a frequency bandwidth may be specified by an absolute
amount (such as 5 MHz) or a relative amount (such as 1/3 of an
available frequency channel). As an example, a femto base station
may be configured to use a third of the bandwidth of the
appropriate wireless channel. If the wireless channel was 6 MHz,
the femto base station would be configured to use a frequency
bandwidth of 2 MHz.
Controlling the frequency bandwidths of femto base stations using
traditional network planning techniques may not be particularly
suitable in a network with a large number of femto base stations
due to the cost and the difficulty of obtaining detailed geometry
and propagation information for the femto base stations. Moreover,
because a user has control over a femto base station, the user may
turn it on or off at any give time, or may move the femto base
station to a different location. This may potentially outdate
information used to plan the network. Thus, an operator of a
network with many femto base stations may desire to configure
and/or optimize the network in real time.
In some embodiments, a method for tuning frequency bandwidth
allocations in a network may be provided. In certain embodiments,
femto base station 104 may not communicate with other base stations
(such as femto base stations 136 or 140) of the WSP's network and
may be considered a player in a non-cooperative game trying to
maximize its own benefit. In such embodiments, each femto base
station may balance a data throughput gain against a cost
associated with increasing the amount of frequency bandwidth used.
In some embodiments, femto base station 104 may adjust the amount
of frequency bandwidth that it is using to communicate with one or
more of endpoints 124 or 128 based on, for example, a bandwidth
updating algorithm that takes into account the quality of the
signals 130 and 134 between femto base station 104 and endpoints
124 and 128, and a cost per unit of frequency bandwidth. In some
embodiments, the algorithm may also take into account one or more
network tuning constants. These tuning constants may be adjusted,
for example by server 152, to adjust the equilibrium point of femto
base stations 104, 136, and 140. Femto base station 104 may update
its frequency bandwidth periodically using the bandwidth updating
algorithm. In some embodiments, when a plurality of base stations
in a network update their respective frequency bandwidths in a
similar fashion, the network as a whole may converge to a unique
Nash equilibrium of the non-cooperative game (e.g., where every
base station will operate at its optimal frequency bandwidth at
Pareto optimality). For example, in a network with a plurality of
femto base stations, a frequency bandwidth set comprising the
frequency bandwidth of each femto base station may approach and/or
converge to a Nash equilibrium. In various embodiments, the
bandwidth updating algorithm may be used by femto base stations or
any other suitable base station. The Nash equilibrium point may be
adjusted by updating the network tuning constants used by the femto
base stations.
Various components shown in FIG. 1 (e.g., femto base stations 104,
136, 140, macro base station 144, server 152, and endpoints 124 and
128) may include one or more portions of one or more computer
systems. In particular embodiments, one or more of these computer
systems may perform one or more steps of one or more methods
described or illustrated herein. In particular embodiments, one or
more computer systems may provide functionality described or
illustrated herein. In some embodiments, encoded software running
on one or more computer systems may perform one or more steps of
one or more methods described or illustrated herein or provide
functionality described or illustrated herein.
The components of one or more computer systems may comprise any
suitable physical form, configuration, number, type and/or layout.
As an example, and not by way of limitation, one or more computer
systems may comprise an embedded computer system, a system-on-chip
(SOC), a single-board computer system (SBC) (such as, for example,
a computer-on-module (COM) or a system-on-module (SOM)), a desktop
computer system, a laptop or notebook computer system, an
interactive kiosk, a mainframe, a mesh of computer systems, a
mobile telephone, a personal digital assistant (PDA), a server, or
a combination of two or more of these. Where appropriate, one or
more computer systems may be unitary or distributed; span multiple
locations; span multiple machines; or reside in a cloud, which may
include one or more cloud components in one or more networks.
Where appropriate, one or more computer systems may perform without
substantial spatial or temporal limitation one or more steps of one
or more methods described or illustrated herein. As an example, and
not by way of limitation, one or more computer systems may perform
in real time or in batch mode one or more steps of one or more
methods described or illustrated herein. One or more computer
systems may perform at different times or at different locations
one or more steps of one or more methods described or illustrated
herein, where appropriate.
In particular embodiments, a computer system may include a
processor, memory, storage, and a communication interface. As an
example, a femto base station (such as femto base station 104) may
comprise a computer system that includes processor 108, memory 112,
storage 114, and communication interface 120. These components may
work together in order to provide base station functionality, such
as increasing the efficiency with which the available wireless
resources are used. More specifically, the components of femto base
station 104 may allow femto base station 104 to select and use
particular settings for its wireless connection or connections
(such as 130 and 134) with one or more endpoints (such as 124 and
128) based on, for example, network tuning constants from server
152 and one or more signal performance measurements from endpoints
124 and/or 128.
Processor 108 may be a microprocessor, controller, or any other
suitable computing device, resource, or combination of hardware,
stored software and/or encoded logic operable to provide, either
alone or in conjunction with other femto base station 104
components, such as memory 112, femto base station functionality.
Such functionality may include providing various wireless features
discussed herein to an endpoint, base station, and/or relay
station. Certain features provided by femto base station 104 via,
in part, processor 108 may allow system 100 to support more
endpoints and/or provide improved quality of service, as compared
to a traditional wireless network.
Memory 112 may be any form of volatile or non-volatile memory
including, without limitation, magnetic media, optical media,
random access memory (RAM), read-only memory (ROM), flash memory,
removable media, or any other suitable local or remote memory
component or components. Memory 112 may store any suitable data or
information utilized by femto base station 104, including software
embedded in a computer readable medium, and/or encoded logic
incorporated in hardware or otherwise stored (e.g., firmware).
Storage 114 may be any form of volatile or non-volatile memory
including, without limitation, magnetic media, optical media,
random access memory (RAM), read-only memory (ROM), flash memory,
removable media, or any other suitable local or remote memory
component or components. Storage 114 may store any suitable data or
information utilized by femto base station 104, including software
embedded in a computer readable medium, and/or encoded logic
incorporated in hardware or otherwise stored (e.g., firmware). In
some embodiments, data may be loaded from storage 114 and stored in
memory 112, or loaded from memory 112 and stored in storage
114.
In some embodiments, memory 112 may store information used by
processor 108 in determining parameters for a wireless connection.
Memory 112 may also store the results and/or intermediate results
of the various calculations and determinations performed by
processor 108. In some embodiments, memory 112 may also store
information regarding the wireless connection being used by each
endpoint (such as 124 and 128) connected to femto base station
104.
Femto base station 104 may also comprise communication interface
120 which may be used for the communication of signaling and/or
data between femto base station 104 and one or more networks (such
as ISP network 132 or WSP network 148). For example, communication
interface 120 may perform any formatting or translating that may be
needed to allow femto base station 104 to send and receive data to
and from ISP network 132 over a wired connection. Communication
interface 120 may also be used to establish any wired connections
between femto base station 104 and other networks or network
components. In particular embodiments, communication interface 120
may provide a backhaul connection to the WSP's network 148 via the
user's internet access supplied by an ISP (which may be the same or
a different entity than the WSP).
In some embodiments, components of system 100 (e.g., femto base
stations 104, 136, and 140, macro base station 144, and endpoints
124 and 128) may also comprise a radio and antenna for wireless
communication. As an example, femto base station 104 comprises a
radio 122 that may be coupled to or a part of antenna 126. Radio
122 may receive digital data that is to be sent out to other base
stations, relay stations, and/or endpoints via a wireless
connection (such as 130). The wireless connection may use the
wireless resources assigned to or by femto base station 104. The
wireless resources may include, for example, a combination of one
or more of a center frequency, frequency bandwidth, time slot,
channel, and/or sub-channel. In particular embodiments, this
information may be stored in memory 112. Radio 122 may convert the
digital data into a radio signal having the appropriate center
frequency and bandwidth parameters. These parameters may have been
determined ahead of time by some combination of processor 108 and
memory 112. The radio signal may then be transmitted via antenna
126 for receipt by any appropriate component or device (e.g.,
endpoint 124). Similarly, radio 122 may convert radio signals
received from antenna 126 into digital data to be processed by
processor 108.
Antenna 126 may be any type of antenna capable of transmitting and
receiving data and/or signals wirelessly. In some embodiments,
antenna 126 may comprise one or more omni-directional, sector or
panel antennas operable to transmit/receive radio signals between 2
GHz and 66 GHz. An omni-directional antenna may be used to
transmit/receive radio signals in any direction, a sector antenna
may be used to transmit/receive radio signals from devices within a
particular area, and a panel antenna may be a line of sight antenna
used to transmit/receive radio signals in a relatively straight
line. Radio 122 and antenna 126 may collectively form a wireless
interface. This wireless interface may be used to establish
connections with various wireless components, including endpoints
and relay stations.
Endpoints 124 and 128 may be any type of endpoints operable to
wirelessly send and receive data and/or signals to and from femto
base station 104. Some possible types of endpoints 124 may include
desktop computers, PDAs, cell phones, laptops, and/or VoIP phones.
In some embodiments, endpoint 124 may comprise a processor, memory,
storage, radio, antenna, and/or other components that enable the
functionality of endpoint 124. In some embodiments, these
components may work together in order to provide endpoint
functionality, such as communicating with femto base station 104.
In some embodiments, the components of endpoint 124 may allow
endpoint 124 to detect various factors and determine a signal
performance associated with wireless connection 130 between
endpoint 124 and femto base station 104. This information may then
be communicated to femto base station 104 using any of a variety of
reporting techniques.
A processor of endpoint 124 may provide various wireless features
discussed herein to endpoint 124. For example, in particular
embodiments, a processor may be able to determine a signal
performance measurement, such as a signal to interference and noise
ratio (SINR). In some embodiments, information relating to signal
performance (e.g., signal strength, interference, and noise) may be
provided by a wireless interface (e.g., a radio and antenna) of the
endpoint.
A memory of the endpoint 124 may store any suitable data or
information utilized by the endpoint. In some embodiments, memory
may store information used by the endpoint's processor in
determining the signal performance. For example, a memory may store
parameters, measurements, and/or other information collected by
endpoint 124 that relates to the quality of wireless connection
130. A memory may also store the results and/or intermediate
results of the various calculations and determinations performed by
the endpoint's processor.
Endpoint 124 may also comprise a radio that is coupled to or a part
of an antenna to send/receive digital data to/from, for example,
femto base station 104 via a wireless connection 130. In particular
embodiments, information related to the wireless connection 130
(e.g., the wireless resources assigned to endpoint 124) may be
stored in a memory of endpoint 124. The radio may convert digital
data into a radio signal having the appropriate center frequency
and bandwidth parameters. These parameters may have been determined
ahead of time and stored in the endpoint's memory. The radio signal
may then be transmitted for receipt by any appropriate component or
device (e.g., femto base station 104). Similarly, the endpoint's
radio may convert radio signals received from a device (e.g., femto
base station 104) into digital data to be processed by the
endpoint's processor.
In the embodiment depicted, system 100 also includes server 152.
Server 152 may assist in the management of radio resources used by
the base stations of WSP network 148. In particular embodiments,
server 152 may be a SON server. In some embodiments, server 152 may
be operable to perform any calculations described herein on behalf
of one or more femto base stations 104, 136, and 140, macro base
station 144, another base station, a relay station, or another
server. In some embodiments, server 152 may provide one or more
frequency bandwidths and/or network tuning constants for one or
more base stations and/or relay stations of a network. Server 152
may comprise a computer system that includes processor 156, memory
160, storage 164, and communication interface 170. These components
may work together in order to provide server functionality (e.g.,
SON server functionality), such as adjusting how the available
wireless resources are used. In some embodiments, the components of
server 152 may allow server 152 to provide both global and local
adjustments to the network tuning constants of the femto base
stations (e.g., femto base station 104). The global adjustments to
the network tuning constants may be uniformly applicable to all the
femto base stations, whereas the local adjustments to the network
tuning constants may be directed to specific femto base stations.
This may allow a wireless service provide great flexibility in how
its wireless resources are used. For example, the wireless service
provider may provide better service to certain customers who pay
higher fees or increase the service to femto base stations within a
particular area during a particular event (e.g., a convention,
sporting event, concert, parade, etc.).
In certain embodiments, the components of server 152 may also allow
server 152 to select particular settings for the wireless
connections of femto base stations 104, 136, 140, and/or macro base
station 144 of the WSP network 148.
Processor 156 may be a microprocessor, controller, or any other
suitable computing device, resource, or combination of hardware,
stored software and/or encoded logic operable to provide, either
alone or in conjunction with other server 152 components, such as
memory 160, server functionality. Such functionality may include
managing various wireless features discussed herein for a base
station or other network component. Certain features provided by
server 152 via, in part, processor 156 may allow system 100 to
support more base stations and/or provide improved quality of
service, as compared to a traditional wireless network. For
example, processor 156 may calculate a frequency bandwidth and/or a
network tuning constant. In certain embodiments, server 152 may
provide certain femto base stations with additional resources based
on a subscription plan or special event. For example, if a user
subscribes to a higher service plan, server 152 may provide the
respective femto base station with one or more network tuning
constants that increase the frequency bandwidth for that femto base
station.
Memory 160 may be any form of volatile or non-volatile memory
including, without limitation, magnetic media, optical media,
random access memory (RAM), read-only memory (ROM), flash memory,
removable media, or any other suitable local or remote memory
component or components. Memory 160 may store any suitable data or
information utilized by server 152, including software embedded in
a computer readable medium, and/or encoded logic incorporated in
hardware or otherwise stored (e.g., firmware). In some embodiments,
memory 160 may store information (e.g., a signal performance
measurement) used by processor 156 in determining parameters for a
wireless connection, such as a frequency bandwidth or a network
tuning constant. Memory 160 may also store the results and/or
intermediate results of the various calculations and determinations
performed by processor 156. In some embodiments, memory 160 may
store information which may be used in determining which femto base
stations should be able to use more frequency bandwidth. For
example, memory 160 may comprise a table, database, or other
collection of data, that identifies the location and timing of
major events and/or that lists users who have subscribed to a
higher or lower level of service.
Storage 164 may be any form of volatile or non-volatile memory
including, without limitation, magnetic media, optical media,
random access memory (RAM), read-only memory (ROM), flash memory,
removable media, or any other suitable local or remote memory
component or components. Storage 164 may store any suitable data or
information utilized by server 152, including software embedded in
a computer readable medium, and/or encoded logic incorporated in
hardware or otherwise stored (e.g., firmware). In some embodiments,
data may be loaded from storage 164 and stored in memory 160, or
loaded from memory 160 and stored in storage 164.
Server 152 may also comprise communication interface 172 which may
be used for the communication of signaling and/or data between
server 152 and one or more networks (such as ISP network 132 or WSP
network 148) and/or network components, such as femto base stations
104, 136, 140, and macro base station 144. For example,
communication interface 172 may perform any formatting or
translating that may be needed to allow server 152 to send and
receive data to and from WSP network 148 over a wired connection.
Communication interface 172 may also be used to establish any wired
connections between server 152 and other networks or network
components.
System 100 may comprise a network that includes various networks,
such as ISP network 132 and WSP network 148. In some embodiments, a
network may comprise one or more networks, such as the Internet, a
LAN, WAN, MAN, PSTN, or some combination of the above. In certain
embodiments, ISP network 132 may be coupled to WSP network 148 via
one or more networks, including but not limited to, the Internet, a
LAN, WAN, MAN, PSTN, or some combination of the above. In some
embodiments, an ISP may provide a user with his home network
access. A user may use the ISP network 132 for home network access
at the user's home location. In providing the user with home
network access, the ISP network 132 may include modems, servers,
gateways (e.g., an ISP gateway), and/or other suitable components.
In some embodiments, ISP network 132 may provide backhaul access
from a base station (such as 104) to WSP network 148.
In particular embodiments, WSP network 148 may comprise various
servers (such as 152), gateways, switches, routers, and other nodes
used in providing wireless service. In some embodiments, the
servers may comprise one or more servers, such as Operation,
Administration, Maintenance and Provisioning (OAM&P) servers,
Network Access Provider (NAP) servers, AAA servers, Self Organizing
Network (SON) servers, or any other servers that the WSP may need
to configure/authenticate one or more base stations (such as 104)
and provide users with wireless service. The WSP's gateways may
comprise any hardware and/or software needed to couple WSP network
148 with ISP network 132. For example, in particular embodiments,
the gateway may comprise a security gateway and, behind the
security gateway, an ASN gateway. In some embodiments, the WSP
network 148 may support and/or implement orthogonal
frequency-division multiple access (OFDMA).
In various embodiments, WSP network 148 may comprise various types
of relay stations and/or base stations, such as a macro, micro,
pico, femto, or other type of base station. In some embodiments,
the bandwidth updating algorithm may be used by any of these base
stations. In some embodiments, one or more calculations involved in
implementing the bandwidth updating algorithm may be performed by
femto base station 104, server 152, or other suitable component of
the network.
In some embodiments, various base stations (e.g., the macro base
stations) of the network may be optimized through planning and
tuning, rather than through a bandwidth updating algorithm as
described herein. In various embodiments, a plurality of base
stations of the network may use a common bandwidth updating
algorithm, even if they are different types of base stations (e.g.,
pico and femto).
System 100 may also include femto base stations 104, 136, 140, and
macro base station 144 and/or other wireless communication devices
that produce interference during wireless communication between,
for example, femto base station 104 and its endpoints 124 and 128.
Limited frequency spectrum allocated for wireless communication and
a high density of base stations (e.g., femto base stations) in a
network may intensify this interference, leading to loss of signal
and/or quality of service. In some embodiments, network performance
may be improved through a bandwidth updating algorithm used by the
base stations (such as femto base stations 104, 136, and 140,
and/or macro base station 144) of a network.
In some embodiments, femto base station 104 may be a base station
"i" of a network comprised of "N" base stations operating in the
same frequency channel. In some embodiments, femto base station 104
may communicate wirelessly for a period of time with at least one
endpoint 124 (and/or 128) using a first frequency bandwidth. For
example, femto base station 104 may use all or a portion of a
frequency channel with a bandwidth of 10 Megahertz (MHz). The
normalized bandwidth used by femto base station 104 may be
represented as w.sub.i. For example, femto base station 104 with a
normalized bandwidth w.sub.i=0.5 may wirelessly communicate using a
first frequency bandwidth of 5 MHz of the 10 MHz channel.
In some embodiments, the first frequency bandwidth does not have to
be contiguous. For example, in an OFDMA scheme, a frequency channel
may comprise various frequency subcarriers. In some embodiments,
the average transmission power per subcarrier may be fixed. In some
embodiments, femto base station 104 may randomly (e.g.,
pseudo-randomly) select frequency subcarriers from the frequency
channel. This may allow the interference produced by femto base
station 104 (and other base stations employing this technique) to
be spread across one or more frequency channels used by femto base
station 104.
In some embodiments, a base station may use a set of frequency
subcarriers for a first period of time, a different set of
frequency subcarriers for a second period of time, and so on. In
some embodiments, the frequency subcarriers may or may not be
contiguous. In some embodiments, a base station may use various
subcarriers by occupying a subset of physical resource blocks in an
LTE communication scheme or a subset of PUSC subchannels in a WiMAX
communication scheme.
As femto base station 104 communicates wirelessly with at least one
endpoint 124 for a period of time, endpoint 124 may measure the
signal performance of the wireless communication. For example, the
endpoint 124 may perform an SINR calculation for the wireless
signal from femto base station 104 to the endpoint 124 or other
suitable measurement that determines a quality of the wireless
signal. The signal performance may generally be impacted by the
transmission power and bandwidth usage of the other wireless
communication devices of the network (such as femto base stations
136 and 140 and macro base station 144). Accordingly, the signal
performance measurement (e.g., SINR) may incorporate the
interference received from surrounding base stations. In some
embodiments, endpoint 124 may communicate the signal performance
measurement to femto base station 104. In some embodiments, other
endpoints (such as 128) that communicate with femto base station
104 may communicate a similar measurement. In some embodiments,
femto base station 104 (or other suitable network component) may
assimilate multiple signal performance measurements from its
endpoints into one signal performance measurement which can be
designated for exemplary purposes as SINR.sub.i. Femto base station
104 may use any suitable method for assimilating signal performance
measurements, such as averaging.
In some embodiments, the signal performance measurement may be used
to determine a data throughput of femto base station 104. The data
throughput is indicative of the quality of service provided by
femto base station 104 and may depend in part on the frequency
bandwidth and signal performance of femto base station 104. The
data throughput may be determined in any suitable manner. For
example, femto base station 104 may track an amount of data
transmitted by femto base station 104 over a period of time. As
another example, in some embodiments, a data throughput (R.sub.i)
of femto base station 104 may be approximated using the Shannon
channel capacity. For example:
R.sub.i=w.sub.iln(1+.beta.SINR.sub.i) where 0<.beta.<1 may
represent the gap between the realized modulation and coding scheme
(MCS) and the Shannon capacity. In some embodiments, the
performance measurement may comprise the bandwidth and data
throughput. The performance measurement may be sent to server 152
for determining potential future network tuning constant
adjustments.
In some embodiments, femto base station 104 may calculate its own
data throughput R.sub.i. In other embodiments, femto base station
104 may communicate its frequency bandwidth w.sub.i and SINR.sub.i
to another node (such as server 152) for calculation of the data
throughput R.sub.i.
In some embodiments, the data throughput R.sub.i and frequency
bandwidth w.sub.i of femto base station 104 over a time interval t
may be used to calculate a frequency bandwidth for femto base
station 104 to use during a next interval t+1 of wireless
communication with its one or more endpoints. In some embodiments,
femto base station 104 may try to maximize a net utility function
NU.sub.i based on the data throughput R.sub.i of femto base station
104 and a cost per unit of frequency bandwidth c.sub.i used by
femto base station 104. For example, the net utility of femto base
station 104 may be represented as:
NU.sub.i(w.sub.i,R.sub.i)=U.sub.i(R.sub.i(w.sub.i))-c.sub.iw.sub.i
where U.sub.i(R.sub.i(w.sub.i)) is the utility of the data
throughput R.sub.i of femto base station 104 when it uses frequency
bandwidth w.sub.i. Thus, the net utility may be based on the data
throughput R.sub.i at a given frequency bandwidth w.sub.i and the
cost c.sub.i of using the frequency bandwidth w.sub.i. In some
embodiments, the cost c.sub.i may influence the net utility that
femto base station 104 provides when the femto base station uses
frequency bandwidth w.sub.i to communicate with its endpoints. In
some embodiments, the cost c.sub.i is a value configured to
discourage excessive use of frequency bandwidth by femto base
station 104. As an example, if there was no cost c.sub.i associated
with frequency bandwidth usage, each femto base station might try
to maximize its own utility by using all of its available frequency
bandwidth. This would likely result in suboptimal system
performance due to the excessive interference that would be
generated by the femto base stations of the network. In some
embodiments, the cost term c.sub.i may be determined and/or
supplied by server 152, which in some embodiments may be a SON
server.
In some embodiments, the only interaction between base stations
(such as femto base stations) in a network may be the interference
they cause each other. In some embodiments, a femto base station
104 may adjust its frequency bandwidth w.sub.i to maximize its own
net utility. Checking the first order optimality condition by
taking the derivative of the net utility equation with respect to
w.sub.i (and keeping in mind the constraint
0.ltoreq.w.sub.i.ltoreq.1) yields the following result, hereafter
referred to as "Result A":
.function..function..beta..function..times..function..function..beta..fun-
ction. ##EQU00001## ##EQU00001.2##
.function.d.function.d'.function. ##EQU00001.3## and W=[w.sub.0, .
. . , w.sub.N-1].sub.T
Since SINR.sub.i is a function of W, this equation for optimal
frequency bandwidth w.sub.i* does not provide a direct solution to
the optimum value of w.sub.i. However, it provides the basis for an
iterative algorithm of updating w.sub.i. In some embodiments, the
utility function U.sub.i may be chosen such that it is an
increasing and concave function of data throughput R.sub.i of a
base station. In particular embodiments, the utility function
U.sub.i may be chosen so that iterative updates allow the network
to converge to a unique Nash equilibrium W*.
In general, a Nash equilibrium may be a solution set of a game
involving two or more players, in which each player is assumed to
know the equilibrium strategies of the other players, and in which
no player has anything to gain by changing only his or her own
strategy unilaterally. In particular embodiments, the process that
each base station uses to update its bandwidth usage, based on the
bandwidth usage of the other base stations in the network, may be
viewed as a non-cooperative game where each player (base station)
tries to maximize its own benefit (net utility NU.sub.i) by
adjusting its strategy w.sub.i. Thus, a Nash equilibrium may be the
set W*=[w*.sub.o, . . . , w*.sub.N-1].sup.T, where W* satisfies:
NU.sub.i(w*.sub.i,W*.sub.-i).gtoreq.NU.sub.i(w'.sub.i,W*.sub.-i)
for all 0.ltoreq.w'.sub.i.ltoreq.1, 0.ltoreq.i.ltoreq.N-1.
At W*, each base station has maximized its own net utility NU.sub.i
as long as the frequency bandwidth usage by each base station of
the network remains constant. Thus, in some embodiments, iterative
updates of the frequency bandwidths used by the base stations of a
network may allow the network to approach and/or converge to a Nash
equilibrium and achieve Pareto optimality. That is, a set that
comprises a frequency bandwidth for each base station of the
network may approach and eventually converge to a Nash
equilibrium.
In some embodiments, the choice of the utility function U.sub.i may
allow the network to converge to a Nash equilibrium as the base
stations periodically update their respective frequency bandwidths.
In general, an iterative algorithm may converge to a unique fixed
point if it is a standard function, that is, the algorithm
satisfies the conditions of positivity, monotonicity, and
scalability. In some embodiments, the utility function may be
chosen such that the bandwidth updating algorithm is a standard
function, thus allowing convergence. For example, a utility
function of the form U.sub.i(x)=-a.sub.ix.sup.-k.sup.i,
a.sub.i>0,k.sub.i>0 may allow the network to converge to a
Nash equilibrium. Utilizing this equation in conjunction with the
equation for optimal frequency bandwidth w*.sub.i listed above
(e.g., plugging this equation into Result A) yields an exemplary
bandwidth updating algorithm of:
.gamma..function. ##EQU00002## where t is the number of the update
interval,
.gamma..alpha..times..times..times. ##EQU00003## In some
embodiments, a.sub.i may equal one. In other embodiments, a.sub.i
may be a hysteresis parameter that varies with each update.
In some embodiments, l.sub.i and y.sub.i are network tuning
constants that can be tuned to adjust the Nash equilibrium of
system 100. In some embodiments, the tuning constants may be
configured to effectuate a policy scheme of the system, such as
network-wide data throughput, fairness, or other policy
consideration. In some embodiments, the network tuning constants
may be adjusted based on the network load. These network tuning
constants may be supplied and/or calculated in any suitable manner.
For example, a base station may be pre-configured (e.g., during
manufacturing or before deployment in a network) to use one or more
particular network tuning constants. As another example, one or
more of these network tuning constants may be supplied by a server,
such as server 152. In some embodiments, one or more network tuning
constants may be supplied periodically, upon start up of femto base
station 104, in response to a triggering event (e.g., when a new
femto base station joins wireless network 148), and/or at any other
suitable time. The network tuning constants may be updated by any
suitable entity, such as server 152. In some embodiments, an update
to a network tuning constant may be based on the frequency
bandwidth w.sub.i and/or data throughput R.sub.i of a base station
over an interval of time t. In various embodiments, a base station
of a network may be assigned network tuning constants that are
tailored for that particular base station. Thus, in some
embodiments, different network tuning constants may be used for
different base stations.
In certain embodiments, the network tuning constants l.sub.i and
y.sub.i may conform to the following parameters:
<< ##EQU00004## ##EQU00004.2## .gamma.> ##EQU00004.3##
Adjusting l towards 0 will move the equilibrium point towards a
resource fair environment in which each base station uses an
approximately equal amount of resources (e.g., bandwidth) and
adjusting l towards 1 will move the equilibrium point towards a
rate fair environment in which each base station provides an
approximately equal data rate. Furthermore, increasing y.sub.i for
a particular base station may increase the data throughput of the
corresponding base station. In certain embodiments, l may be a
global network tuning constant and y may be a local network tuning
constant. For example, server 152 may determine an appropriate
value for l based in part on one or more parameters provided by the
WSP. The WSP parameters may relate to a baseline, or standard,
performance characteristic for the base stations of the WSP's
wireless network. The l network tuning constant may be used to
determine a baseline y. Both l and y may then be distributed
uniformly to all the base stations within the control of server
152. Server 152 may then further fine tune the performance of
specific base stations or groups of base stations by adjusting y
for specific base stations or groups of base stations. For example,
server 152 may increase y for those base stations associated with a
higher subscription level. In some embodiments, the base stations
may provide server 152 with their respective data throughput,
bandwidth usage, and/or any other signal performance measurements.
These may be used by server 152 to adjust the network tuning
constants.
In some embodiments, a frequency bandwidth for femto base station
104 to use during a future time interval t+1 may be calculated
using the bandwidth updating algorithm described above. The
calculated frequency bandwidth may be based on the data throughput
R.sub.i and bandwidth w.sub.i of a previous time interval t, and
the network tuning constants l.sub.i and y.sub.i. In some
embodiments, a table of X.sup.-l.sup.i may be pre-computed and
stored in memory (e.g., 112 or 160) or storage (e.g., 114 or 164)
in order to aid in the computation of
##EQU00005## by reducing the operation to a table lookup. This may
be particularly helpful when the frequency bandwidth is calculated
by a base station (such as femto base station 104), or when server
152 must quickly calculate frequency bandwidths for numerous base
stations of a network.
After a frequency bandwidth w.sub.i for the next time interval t+1
has been calculated, the new frequency bandwidth may be used to
communicate wirelessly with at least one of endpoints 124 or 128.
As with the first frequency bandwidth, the new frequency bandwidth
may comprise a plurality of frequency subcarriers that are randomly
selected. After a time interval has passed, the frequency bandwidth
may be updated again according to the bandwidth updating algorithm.
This process may repeat any number of times.
In some embodiments, femto base station 104 may periodically update
its frequency bandwidth usage w.sub.i in order to maximize its own
net utility. In particular embodiments, the length of the update
interval may be long enough for a determination of the data
throughput R.sub.i of femto base station 104, while short enough to
accommodate changes in the network, such as a change of load or
number of endpoints communicating with a base station of the
network, the powering up or down of a base station, changes in
channel gain of a base station, or changes in noise. In various
embodiments, the base stations of a network may update their
respective frequency bandwidths synchronously or asynchronously
with respect to the other base stations.
FIG. 2 depicts various architectures that may be used for
allocating bandwidth in a network. Some embodiments may include a
distributed architecture utilizing architecture 200. In a
distributed architecture, the nodes 208, 212, and 216 of the
network may be responsible for calculating their respective
frequency bandwidths. In some embodiments, a node may use any
suitable information to calculate a frequency bandwidth, such as
its frequency bandwidth and data throughput over a time interval
and one or more network tuning constants. In some embodiments, the
network tuning constants may be supplied by server 204. After
calculating a new frequency bandwidth, the node 208 may use the new
frequency bandwidth to communicate with its endpoints. The signal
performance value of the new frequency bandwidth may be provided to
server 204 for future determinations. The distributed architecture
is highly scalable, since each added node is expected to calculate
its own frequency bandwidths, thus reducing the load on server
152.
Some embodiments may include a centralized architecture utilizing
architecture 200. In a centralized architecture, server 204 may
calculate frequency bandwidths for the nodes 208, 212, and 216 of
the network. For example, the server 204 may determine a frequency
bandwidth set comprising a frequency bandwidth for each of the
nodes 208, 212, and 216. In some embodiments, nodes 208, 212, and
216 may report one or more parameters to server 204. For example,
node 208 may report its frequency bandwidth w.sub.i and data
throughput R.sub.i over a time interval to server 204. The server
may use these parameters to calculate new network tuning constants
and/or a new frequency bandwidth w.sub.i for node 208.
In some embodiments, server 204 may also use one or more network
tuning constants to calculate the frequency bandwidths. In some
embodiments, the one or more network tuning constants may be based
on the parameters received from one or more of nodes 208, 212, and
216. For example, since server 204 may receive data from various
nodes 208, 212, and 216, it may determine that a particular node
208 should have a higher frequency bandwidth and may update one or
more network tuning constants accordingly.
In particular embodiments, the Nash equilibrium of the network may
be tuned to provide a system preference, such as network-wide data
throughput, fairness, or other policy considerations. As the
network tuning constants are updated and new frequency bandwidths
are calculated, the wireless network may converge on the tuned
preferences. In some embodiments, the process of updating the
network tuning constants may be transparent to the nodes since they
receive the updated frequency bandwidth (which incorporates the
network tuning constants). In some embodiments, server 204 may
communicate a newly calculated frequency bandwidth to node 208.
Node 208 may then use the new frequency bandwidth to communicate
with one or more of its endpoints.
Some embodiments may include a hybrid architecture utilizing
architecture 200. In a hybrid architecture, nodes 208, 212, and 216
of the network may be responsible for calculating their respective
frequency bandwidths and may report one or more parameters to
server 204. For example, a node may report its frequency bandwidth
w.sub.i and data throughput R.sub.i over a time interval to server
204. In some embodiments, these parameters may be transferred from
node 208 to server 204 using a standard network management
interface. The server may use these parameters to calculate one or
more network tuning constants (such as l.sub.i, y.sub.i) in any
suitable manner, such as that described above with respect to the
centralized architecture. The server may then communicate these
tuning constants to node 208. Node 208 may then calculate a new
frequency bandwidth w.sub.i based on these tuning constants (and a
measured data throughput and frequency bandwidth of the node). Node
208 may then use the new frequency bandwidth to communicate with
its endpoints.
In comparison with the centralized architecture (where the server
may perform the bulk of the calculations), the hybrid approach is
more scalable since the individual nodes calculate their respective
frequency bandwidths. In the centralized architecture the nodes of
the network are not required to implement the bandwidth updating
algorithm (and thus nodes that do not have this capability would
still be able to update their frequency bandwidth based on values
calculated by the server). In both the centralized and hybrid
architectures, nodes 208, 212, and 216, and server 204 exchange a
minimal amount of data, thus maintaining a low communication
overhead.
Some embodiments may include a hierarchical architecture utilizing
architecture 250. A hierarchical architecture may comprise various
subnets. Each subnet may comprise one of subnet servers 258 or 274
and a plurality of nodes coupled to the subnet server. In some
embodiments, each subnet server may be coupled to a central server
254. In some embodiments, a hierarchical architecture may include
any number of subnets.
In some embodiments, a subnet may employ a centralized or hybrid
architecture as described above. In some embodiments, a subnet
server may communicate information received from one or more of its
respective nodes to central server 254. For example, subnet server
258 may communicate a frequency bandwidth w.sub.i or a data
throughput R.sub.i of a node 262 to central server 254. In some
embodiments, a subnet server may determine one or more network
tuning constants for its nodes and communicate these network tuning
constants to central server 254. In some embodiments, central
server 254 may calculate any suitable parameter (such as a
frequency bandwidth or a network tuning constant) for any node in
its network.
In some embodiments, central server 254 may coordinate the entire
network. For example, the central server may manage the radio
resources used in the network. In other embodiments, the
network-wide coordination may be performed in a distributed manner
among the subnet servers.
In some embodiments, any combination of the distributed, hybrid,
centralized, and/or hierarchical architectures may be used. For
example, a subset of base stations in a network may calculate their
own frequency bandwidths, while another subset passes information
to a server for the calculation of frequency bandwidths.
FIG. 3 depicts an example of a method for adjusting bandwidth
allocations in a wireless network in accordance with particular
embodiments. In certain embodiments, the method of FIG. 3 may be
performed by a computer, such as the computer described above with
respect to server 152. For purposes of simplicity, the steps of
FIG. 3 are described from the perspective of a server. The method
begins at step 310 where one or more network tuning constants are
provided to each base station within a wireless network. The base
stations may comprise femto base stations. As discussed in more
detail below, the server may use the network tuning constants to
adjust an equilibrium point of a first bandwidth allocation among
one or more base stations within a WSP's wireless network. The
equilibrium point may be a point at which the base stations
collectively arrive between resource fare and rate fare. In some
embodiments, the network tuning constants may comprise two separate
constants. A first network tuning constant may be a global constant
that may be uniformly applied to all the base stations within the
wireless network. A second network tuning constant may be a local
network tuning constant that may be used to fine-tune the data
throughput of individual, or groups of base stations.
Depending on the scenario, the network tuning constants may be
provided by a server, such as a SON server, or they may be
temporary predetermined network tuning constants provided by the
supplier of the base station. Regardless of the source of the
network tuning constants, the network tuning constants values may
comprise a combination of more or more default (e.g. values used at
startup), baseline (e.g., standard value set by the WSP), and/or
adjusted (e.g., at step 350 below) network tuning constant values.
The default network tuning constant values may be the same for each
base station. The actual values may be determined by the
manufacturer and/or the WSP. The default network tuning constant
values may be updated once the base station is able to communicate
with the WSP's network. The baseline network tuning constant values
may reflect a WSP's standard wireless service level. While the WSP
may have a standard wireless service level, the network tuning
constant values used to achieve this level may vary over time and
between wireless networks based on the situation (e.g., number of
users, number of base stations, environmental conditions, etc.).
The adjusted network tuning constant values may reflect either
local or global adjustments to one or more network tuning constants
for one or more base stations. In some cases, the adjusted network
tuning constant values may become the baseline network tuning
constant values.
At step 320 the server may receive signal performance values from
the femto base stations of the wireless network. The signal
performance values may indicate a quality of the wireless
communication between the base station and the end point. In some
embodiments, this may include an efficiency with which data reaches
the end point based on the amount of resources used for the
wireless connection. The signal performance values may comprise the
measured data throughput, the bandwidth usage, information about
the strength of the wireless signal, the interference received on
the wireless signal, or any other signal performance indicator that
may be used by the server to determine network tuning constants, or
the efficiency with which the respective femto base station is
operating. The signal performance values may be received from
individual base stations or subnet servers. The signal performance
values may be received on a periodic basis, upon a triggering
event, or upon request from the server. It may be the case that the
signal performance values may be based on the base stations using a
first frequency bandwidth allocation. This may be used by the
server to determine whether the network tuning constants need to be
adjusted (e.g., at step 330).
At decision step 330 the server determines whether the network
tuning constants should be adjusted. The determination to adjust
the network tuning constants may be based on any of a variety of
factors. For example, in some embodiments, the network tuning
constants may be adjusted upon determining that the current
wireless network performance is above or below a predetermined
threshold (e.g., the based on the WSP's standard service level). As
another example, the network tuning constants may be adjusted in
response to receiving a request from the wireless service provider,
or an operator, to adjust the performance of one or more base
stations within the wireless network. In some scenarios, the
adjustment may be made to only a subset of base stations, or other
base stations, within the wireless network. For example, the
wireless service provider may request a temporary increase to the
data throughput of certain base stations in response to a large
convention or other special event being scheduled. In such a
situation, the server may determine that it needs to adjust the
network tuning constants of the base stations owned by the
convention center and any neighboring businesses so as to increase
their data throughput. As another example, the wireless service
provider may provide two or more different classes of service for
wireless connections. The base stations associated with these
different classes of service may have different sets of network
tuning constants. When a user changes service levels, the server
may adjust the network tuning constants for the corresponding base
station.
At step 340 the server determines the adjustment to be made to the
network tuning constants. In some embodiments, the server may
determine which network tuning constants to adjust, the extent with
which the determined network tuning constants should be adjusted,
and for which base stations the network tuning constants should be
adjusted. In some embodiments, where the server is adjusting a
subset of base stations the server may also determine the impact on
the remaining base stations. It may then adjust all the base
stations. For example, once the server has determined a local
parameter for the subset of base stations, the server may then
readjust the global parameter for all the base stations. In certain
embodiments, the server may determine whether to adjust both the
global parameter and the local parameter for the network tuning
constants, or simply to adjust the local parameter for a select
subset of base stations.
In certain embodiments, the base stations may use the following
equation to determine their resource use:
.gamma..function. ##EQU00006## In such an embodiment, a global
parameter (e.g., l.sub.i) may be moved towards zero to adjust the
equilibrium point towards a resource fair allocation of wireless
resources and towards one to adjust the equilibrium point towards a
rate fare allocation of wireless resources. In addition, a local
parameter (e.g., y.sub.i) may be increased to increase the data
throughput of the corresponding base station. In some scenarios,
the server may determine whether to adjust the equilibrium point
towards a rate fare or a resource fare equilibrium point. This
determination may help in determining how to adjust one or more of
the network tuning constants. For example, the server may compare
the current equilibrium point with a predetermined equilibrium
point to determine how large of an adjustment needs to be made to a
global parameter. As another example, the WSP may generate an
adjustment request if it determines that its macro base stations
are experiencing too much interference from deployed femto base
stations. The server may receive this request and adjust the local,
global, or both network tuning constants so as to reduce the amount
of wireless resources used by the deployed femto base stations.
At step 350 the server adjusts the network tuning constants based
on the signal performance values. The signal performance values may
be used in determining how much of an adjustment to make. The
signal performance values may also be used in determining the
network tuning constants to update for which base stations. For
example, if a particular base station is not performing well, the
server may adjust a local network tuning constant for that base
station to attempt to improve its performance. Along with the
signal performance values received at step 310, the server may also
use any other information indicative of how the network tuning
constants are to be adjusted. For example, the server may use
information about upcoming events. Once the server has determined
and made the adjustments to the network tuning constants, the
method may return to step 310 and the updated network tuning
constants may be provided to the base stations. The steps of the
method depicted in FIG. 3 may be repeated (e.g., periodically or
upon detecting a triggering event, such as detecting a new
endpoint) for as long as the WSP is operating the wireless
network.
While the embodiment depicted in FIG. 3 includes a certain number
of steps, depicted in a certain order, it is to be understood that
other embodiments may have more, fewer or different steps, and the
steps may be rearranged or performed simultaneously. For example,
in some embodiments, the server may initially determine that the
network tuning constants do not need to be adjusted, but then may
receive a request to change one or more network tuning constants
before the server receives additional signal information. In other
words, the "No" branch from decision step 330 may loop back to
decision step 330, not step 320.
The embodiments that this disclosure (including all attachments
hereto) describes or illustrates are examples, and they do not
limit the scope of this disclosure. This disclosure encompasses all
changes, substitutions, variations, alterations, and modifications
to the example embodiments herein that a person having ordinary
skill in the art would comprehend.
Modifications, additions, or omissions may be made to the systems
and apparatuses disclosed herein without departing from the scope
of this disclosure. The components of the systems and apparatuses
may be integrated or separated. Moreover, the operations of the
systems and apparatuses may be performed by more, fewer, or other
components. Additionally, operations of the systems and apparatuses
may be performed using any suitable logic comprising
non-transitory, tangibly stored software, hardware, and/or other
encoded logic. As used in this document, "each" refers to each
member of a set or each member of a subset of a set.
Modifications, additions, or omissions may be made to the methods
disclosed herein without departing from the scope of this
disclosure. The method may include more, fewer, or other steps.
Additionally, steps may be performed in any suitable order.
A component of the systems and apparatuses disclosed herein may
include an interface, logic, memory, and/or other suitable
elements. An interface receives input, sends output, processes the
input and/or output, and/or performs other suitable operation. An
interface may comprise hardware and/or software.
Logic may perform the operations of the component, for example, it
may execute instructions to generate output from input. Logic may
include hardware, software, and/or other logic. Logic may be
encoded in one or more non-transitory and tangible media and may
perform operations when executed by a computer or a processor.
Certain logic, such as a processor, may manage the operation of a
component. Examples of a processor include one or more computers,
one or more microprocessors, one or more applications, and/or other
logic.
In particular embodiments, the operations of the embodiments may be
performed by one or more tangible and non-transitory computer
readable media encoded with a computer program, software, computer
executable instructions, and/or instructions capable of being
executed by a computer. In particular embodiments, the operations
of the embodiments may be performed by one or more computer
readable media storing, embodied with, and/or encoded with a
computer program and/or having a stored and/or an encoded computer
program.
Although this disclosure has been described in terms of certain
embodiments, alterations and permutations of the embodiments will
be apparent to those skilled in the art. Accordingly, the above
description of the embodiments does not constrain this disclosure.
Other changes, substitutions, and alterations are possible without
departing from the spirit and scope of this disclosure, as defined
by the following claims.
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